212 



COMPARATIVE ANATOMY 



The pallium is entirely epithelial in structure (Figs. 160162) : 

 it presents no median involution dividing the anterior part of the 



B 



Lot 



FIG. 160. BRAIN OF SALMON. A, dorsal ; B, ventral ; and C, lateral view. 



Ch, chiasma ; G.p, pineal body ; Jiff, cerebellum ; Hyp, hypophysis ; Jnf, 

 infundibulum ; L.ol, olfactory lobe ; Med, spinal cord ; AfH, mid-brain ; NH, 

 medulla oblongata ; Pall, pallium (in part removed), and BGsmd Ba*G, basal 

 ganglia (corpora striata) of the telencephalon ; <SV, saccus vasculosus ; Tr.opt, 

 optic track; UL, lobi inferiores ; VH, telencephalon ; /-A", cerebral nerves ; 

 1 and 2, first and second spinal nerves (the first represents the hypoglossal, 

 -A. /-*) 



telencephalon into two lateral hemispheres, and is therefore further 

 reduced than in Ganoids: there is a median ventricle. The lower 



